Scientists identify an RNA molecule as a potential target for new Alzheimer's therapies

Göttingen, September 23rd, 2011. Proteins are the molecular machines of the cell. They transport materials, cleave products or transmit signals  and for a long time, they have been a main focus of attention in molecular biology research. In the last two decades, however, another class of critically important molecules has emerged: small RNA molecules, including micro-RNAs. It is now well established that micro-RNAs play a key role in the regulation of cell function."A micro-RNA regulates the production of an estimated 300-400 proteins. This class of molecules can be regarded as a switch that coordinates the transition of cells from one state to another," explains Prof. Dr. André Fischer, scientist at the German Center for Neurodegenerative Diseases (DZNE) and Speaker of the DZNE site Göttingen. He and his team have identified a micro-RNA that regulates the learning processes and probably plays a central role in Alzheimer's disease. The researchers have shown that there is too much of a micro-RNA called "miRNA 34c" in mouse models of Alzheimer's disease, and decreasing the level of miRNA 34c in these mice can restore their learning ability. The scientists have identified a new target molecule that might be important for diagnosis and treatment of Alzheimer's disease. The studies were carried out in collaboration with scientists at the European Neuroscience Institute Göttingen, the Göttingen University, the DZNE site in Munich and researchers from Switzerland, USA and Brazil.

MicroRNAs (miRNAs) are post-transcriptional gene expression regulators, playing key roles in neuronal development, plasticity and disease. Parkinson's disease (PD) is the second most common neurodegenerative disorder, characterized by the presence of protein inclusions or Lewy bodies and a progressive loss of dopaminergic neurons in the midbrain

http://cancerres.aacrjournals.org/content/67/18/8433.full

MicroRNAs (miRNA) are a recently discovered class of noncoding RNAs that negatively regulate gene expression. Recent evidence indicates that miRNAs may play an important role in cancer. However, the mechanism of their deregulation in neoplastic transformation has only begun to be understood.

In the last two decades, however, another class of critically important molecules has emerged: small RNA molecules, including micro-RNAs. It is now well established that micro-RNAs play a key role in the regulation of cell function."A micro-RNA regulates the production of an estimated 300-400 proteins. This class of molecules can be regarded as a switch that coordinates the transition of cells from one state to another

This whole area of research is on the threshold of big breakthroughs. Yesterday I attended a program at Duke University Med School on the neurobiology of various psychological disorders. The specific topic was molecular genetics relating to serotonin receptors and how close they are to identifying the risks for neuropsychiatric diseases in a person. It identifies a predisposition in the genetic transcription controllers which are influenced by the environment to manifest the disease.

At the same time there was a similar grand rounds at the UNC Chapel Hill Med School on the neurobiology of autism, looking at the molecular genetics of the disease.

It’s still a Nature vs. Nurture debate even at the molecular level!!! It’s fascinating research.

A chronically overactive amygdala, the brain region involved in fear, is a hallmark of an unhealthy response to traumatic events. New research, published today (August 30) in Molecular Psychiatry, shows that some soldierswho have no mental health deficits after a return from deploymentalso harbor signs of trauma within the regulatory network of this brain region.

The findings could help researchers determine what changes [in the brain] help us predict who becomes sick and who recovers and leads a normal life, said Ahmad Hariri, a professor at Duke University who was not involved in this study.

The amygdala mediates humans fear response, and researchers have found that its overreaction is related to psychological disorders such as posttraumatic stress disorder (PTSD), anxiety and depression. People with PTSD, for example, have heightened activity in the amygdala when they are exposed to potential stressors, such as images of threatening faces.

In the new study, the researchers compared 23 Dutch combat soldiers who had been deployed to Afghanistan with 16 soldiers who stayed home. They measured brain activity using fMRI as the soldiers were exposed to angry or fearful faces.

The findings revealed different neural responses to the faces depending on how much fear the soldiers experiencedand not necessarily how much combat they were in. Immediately after returning from Afghanistan, those soldiers who reported feeling the greatest threat abroad displayed the most activity in the amygdala when they viewed the faces. Soldiers who didnt feel as threatened had a less sensitive amygdala.

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